[en] If the Higgs boson mass is (125 ± 1) GeV, the standard model cannot be a fundamental theory up to the GUT (Grand Unification) scale due to the vacuum stability arguments. We show that if the dark matter of the Universe consists of stable scalar particles, the vacuum stability constraints are modified and the theory can be valid up to a high scale. We argue that the present LHC data may favour such a scenario. (authors)

[en] We show that if the Higgs boson mass is (125 ± 1) GeV, the CMSSM (Constrained Minimal Supersymmetric Standard Model) sparticle spectrum that is testable at the LHC is restricted only to two distinct possibilities - either of the lightest s-lepton or stop are degenerate in mass with the lightest supersymmetric particle that is the dark matter. This implies that the CMSSM spectrum is now known. However, the two possible options both represent very difficult spectra for the LHC because very soft particles are produced in sparticle decays. We encourage the LHC experiments to perform detailed studies of the two possible CMSSM sparticle spectra. (authors)

[en] If the observed light neutrino masses are induced by their Yukawa couplings to singlet right-handed neutrinos, the natural smallness of those makes direct collider tests of the electroweak scale neutrino mass mechanisms difficult in the simplest models. In the triplet Higgs seesaw scenario the smallness of light neutrino masses may come from the smallness of B-L breaking parameters, allowing sizable Yukawa couplings even for a TeV scale triplet. We show that, in this scenario, measuring the branching fractions of doubly charged Higgs to different same-charged lepton flavors at CERN LHC and/or ILC experiments will allow one to measure the neutrino mass parameters that neutrino oscillation experiments are insensitive to, including the neutrino mass hierarchy, lightest neutrino mass, and Majorana phases

[en] We present the first scientific results, technical details, and recent developments in the Estonian Grid (EG). Ideas and concepts behind Grid technology are described. We mention some most crucial parts of the Grid system, as well as some unique possibilities in the Estonian situation. Scientific applications currently running on the EG are listed and the first scientific computations and results of the EG are discussed. The computations show that the middle ware is well chosen and the EG has remarkable stability and scalability. We present the collected results and experiences of the development of the EG and add some ideas of its near future. (authors)

[en] We have investigated the possibility of direct tests of little Higgs models incorporating triplet Higgs neutrino mass mechanism at LHC experiments. We have performed Monte Carlo studies of Drell-Yan pair production of doubly charged Higgs boson Φ⁺⁺ followed by its leptonic decays whose branching ratios are fixed from the neutrino oscillation data. We propose appropriate selection rules for the four-lepton signal, including reconstructed taus, which are optimized for the discovery of Φ⁺⁺ with the lowest LHC luminosity. As the Standard Model background can be effectively eliminated, an important aspect of our study is the correct statistical treatment of the LHC discovery potential. Adding detection efficiencies and measurement errors to the Monte Carlo analyses, Φ⁺⁺ can be discovered up to the mass 250 GeV in the first year of LHC, and 700 GeV mass is reachable for the integrated luminosity L=30 fb^-1

[en] Taking into account spins, we classify all two-body non-relativistic Dark Matter annihilation channels to the allowed polarization states of Standard Model particles, computing the energy spectra of the stable final-state particles relevant for indirect DM detection. We study the DM masses, annihilation channels and cross sections that can reproduce the PAMELA indications of an e⁺ excess consistently with the PAMELA p-bar data and the ATIC/PPB-BETS e⁺+e^- data. From the PAMELA data alone, two solutions emerge: (i) either the DM particles that annihilate into W,Z,h must be heavier than about 10 TeV or (ii) the DM must annihilate only into leptons. Thus in both cases a DM particle compatible with the PAMELA excess seems to have quite unexpected properties. The solution (ii) implies a peak in the e⁺+e^- energy spectrum, which, indeed, seems to appear in the ATIC/PPB-BETS data around 700 GeV. If upcoming data from ATIC-4 and GLAST confirm this feature, this would point to a O(1) TeV DM annihilating only into leptons. Otherwise the solution (i) would be favored. We comment on the implications of these results for DM models, direct DM detection and colliders as well as on the possibility of an astrophysical origin of the excess

[en] We present a set of recommendations for the presentation of LHC results on searches for new physics, which are aimed at providing a more efficient flow of scientific information between the experimental collaborations and the rest of the high energy physics community, and at facilitating the interpretation of the results in a wide class of models. Implementing these recommendations would aid the full exploitation of the physics potential of the LHC. (authors)

[en] The CMS experiment at CERN is preparing for LHC data taking in several computing preparation activities. In early 2007 a traffic load generator infrastructure for distributed data transfer tests was designed and deployed to equip the WLCG tiers which support the CMS virtual organization with a means for debugging, load-testing and commissioning data transfer routes among CMS computing centres. The LoadTest is based upon PhEDEx as a reliable, scalable data set replication system. The Debugging Data Transfers (DDT) task force was created to coordinate the debugging of the data transfer links. The task force aimed to commission most crucial transfer routes among CMS tiers by designing and enforcing a clear procedure to debug problematic links. Such procedure aimed to move a link from a debugging phase in a separate and independent environment to a production environment when a set of agreed conditions are achieved for that link. The goal was to deliver one by one working transfer routes to the CMS data operations team. The preparation, activities and experience of the DDT task force within the CMS experiment are discussed. Common technical problems and challenges encountered during the lifetime of the taskforce in debugging data transfer links in CMS are explained and summarized.

[en] The goal of this report is to summarize the current situation and discuss possible search strategies for charged scalars, in non-supersymmetric extensions of the Standard Model at the LHC. Such scalars appear in Multi-Higgs-Doublet models, in particular in the popular Two-Higgs-Doublet model, allowing for charged and additional neutral Higgs bosons. These models have the attractive property that electroweak precision observables are automatically in agreement with the Standard Model at the tree level. For the most popular version of this framework, Model II, a discovery of a charged Higgs boson remains challenging, since the parameter space is becoming very constrained, and the QCD background is very high. We also briefly comment on models with dark matter which constrain the corresponding charged scalars that occur in these models. The stakes of a possible discovery of an extended scalar sector are very high, and these searches should be pursued in all conceivable channels, at the LHC and at future colliders. (orig.)

[en] We present a set of recommendations for the presentation of LHC results on searches for new physics, which are aimed at providing a more efficient flow of scientific information between the experimental collaborations and the rest of the high energy physics community, and at facilitating the interpretation of the results in a wide class of models. Implementing these recommendations would aid the full exploitation of the physics potential of the LHC. (orig.)